We establish a law of the iterated logarithm (LIL) for the set of real
numbers whose n-th partial quotient is bigger than αn, where
(αn) is a sequence such that ∑1/αn is finite. This set is
shown to have Hausdorff dimension 1/2 in many cases and the measure in LIL is
absolutely continuous to the Hausdorff measure. The result is obtained as an
application of a strong invariance principle for unbounded observables on the
limit set of a sequential iterated function system.Comment: Improved bounds for $(\alpha_n)